Mining machine having pivotally mounted cutters



Oct. .30, 119162 SIBLEY 3,061,290

EMINI'NG HAVING PIVOTNLLY MOUNTED CUTTERS Filed NOV. 25, 1957 '7 Sheets-Sheet 1 FIG. 2.

mwsmox co JOHN R. SIBLEY:

ATTORNEY.

J. R. SIBLEY Oct. 30, 1962 MINING MACHINE HAVING PIVOTALLY MOUNTED CUITERS Filed Nov. 25, 1957 7 Sheets-Sheet 2 ummnmfimi rn A INVENTOR.

JOH N R. SIBLEY:

A TTORNEY.

Oct. 30, 1962 J. R. SIBLEY 3,061,290

MINING MACHINE HAVING PIVOTALLY MOUNTED CUTTERS Filed Nov. 25, 1957 7 Sheets-Sheet 3 R ATTORNEY.

Oct; 30 5 1 962 J. R. SIBLEY 3 ,961,

MINING MACHINE HAVING PIVOTAELY MOUNTEDT-GUFITERS Filed" NOV. 1957 TSHBGTUS SIIGG'I'. 4

FIG 9 I tea 1 H" IN 39 l I 4 7 9 W, a n a): I h

INVENTOR.

JOHN R. SIBLEY:

ATTORNEY.

J. R. SIBLEY MINING MACHINE HAVING PIVOTALLY MOUNTED CUTTERS Filed Nov. 25, 1957 Oct. 30, 1962 7 Shee ts-Sheet 5 INVENTOR.

9 JOHN R. SIBLEY: v M F 2%,

ATTORNEY.

Oct. 30, 1962 J. R. SIBLEY 3,061,290

MINING MACHINE HAVING PIVOTALLY MOUNTED CUTTERS Filed Nov. 25, 1957 '7 SheetsSheet 6 F I GI 2. 75

J? Y o INVENTOR.

JOHN R. SIBLEY:

BY: 2 z I ATTORNEY.

1962 J. R. SIBLEY 3,061,290

MINING MACHINE HAVING PIVOTALLY MOUNTED CUTTERS Filed Nov. 25, 1957 '7 Shagts-Sheet 7 in V 1 a; 27 FIG.|6. 5! I/K G 4 4/ 3 39 44 a nvmvrox JOHN R. SIBLEY:

BY E Mn% ATTORNEY.

nited States 3,061,290 Patented Get. 30, 1962 flice 3,0613% MINING MACHINE HAVING PIVGTALLY MOUNTED QUTTERS John R. Sihiey, Franklin, Pa assignor to Joy Manufacturing Company, Pittsburgh, Pin, a corporation of Pennsylvania Filed Nov. 25, 1957, Ser. No. 693,498 8 Ciainis. (Cl. 262-9) This invention relates to mining machines and more particularly to a mining and loading machine for dislodging mineral from a solid mine vein and for loading out the dislodged mineral as mining progresses.

The improved mining and loading machine of the preferred illustrative embodiment of the invention is of a low height construction, well adapted to use in mines having low headroom and embodies a full face dislodging mechanism to provide for high production in low veins. The machine advances rectilinearly forwardly as mining progresses and the dislodging mechanism embodies a pair of cutting and dislodging devices pivotally mounted on the mobile base of the machine and extending angularly forwardly and outwardly so that as the base is advanced the mineral is dislodged completely across the face while there remains between the angularly disposed devices a vertical section or pillar, V-shaped in horizontal section, of the solid mineral of the mine vein for supporting the mine roof close to the machine. The cutting and dislodging devices are mounted on the machine base for horizontal adjustment to vary the width of the face and to provide flexibility for turning breakthroughs and for maneuvering the machine. Each cutting and dislodging device comprises superimposed parallel cutter bars having endless cutter chains guided for orbital circulation about their margins and the upper bar may be adjusted vertically to vary the distance apart of the bars to accommodate mine veins of varying heights. The cutter chains, as the base is advanced, cut parallel kerfs in the mineral to form horizontal projections or cores of mineral between the kerfs and mounted for circulation on the lower bar frame are plowlike ripping or tearing instruments or plow elements (which may also be called planer elements) which travel at a speed substantially slower than the cutter chains and serve to rip away or dislodge the projection or core of mineral as mining progresses. The plow elements are of substantial vertical eXtent'and are timed to balance forces on both gangs of cutter bars and minimize any tendency to move the machine olf center. Breaker Wedges under the upper chain tracks serve tobreak' down the core left between the chain kerf and the plow'path. The combined action of the cutter chains and plows movesthe dislodged and disintegrated mineral directly to the centerconveyor 'of the machine and shrouding-is provided at the rear portions of the cutter bars thereby to direct the disintegrated mineral inwardly toward the front receiving portion of the conveyor to facilitate floor cleanup problems. The inwardly and rearwardly moving runs of the cutter chains and the rearwardly moving plow devices at the inner sides of the cutter bars, as they act on themineral of the mine vein during cutting and dislodging thereof, tend to urge the machine forwardly thereby to supplement the crawler base in the forward feeding-of the machine. Further vertical adjustmentof the cutting and dislodging devices will facilitate following vein irregularities and traveling of the machine from place to'place about the mine.

An objectof .the present invention is to provide a low. height, well balanced, full face mining and loading machine whereby production of mineral. in mines having low headroom is substantially increased. Another object is to provide an improved combined mining and loading machine having improved cutting and dislodgingdevices which may be adjusted both in height and horizontally to suit varying mining conditions. A further object is -to provide an improved cutting and dislodging mechanism comprising a pair of forwardly located, angularly disposed cutting and dislodging devices providing a full face and advancing along a straight path during the mining operation. Yet another object is to provide an improved dislodging mechanism comprising a pair of angularly disposed cutting and dislodging devices each having a pair of parallel superimposed cutter bars about the margins of which endless cutter chains are guided for orbital circulation and orbitally movable plowlike ripping or tearing devices or plow elements for ripping away the-projection or core of mineral left between the kerfs or channels formed by the cutter chains. A still further object is to provide an improved cutting and dislodging device comprising parallel superimposed cutter bars for forming parallel horizontal kerfs in the mineral of a mine vein and an orbitally movable ripping or tearing instrument or toothed plow moving relatively slowly in its orbit for dislodging the core of mineral between the kerfs. Yet another object is to provide improved mounting means and driving and adjusting mechanisms for a cutting and dislodging device of a mining machine. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes of illustration one form, from its apparatus aspect, which the invention may assume in practice.

In these drawings:

FIG. 1 is a plan view of a mining and loading machine constructed in accordance with a preferred illustrative embodiment of the invention.

FIG. 2 is a side elevational view of the mining and loading machine shown in FIG. 1.

FIG. 3 is an enlarged vertical section taken on line 3-3 of FIG. 1, showing the superimposed cutter bars and an intermediate plowlike ripper or tearing element.

FIG. 4 is a horizontal section take on line 44 of FIG. 3, showing an endless plow-chain.

FIGS. 5 and 6 are detail vertical sections takenrespectively on line 55 and 66 of FIG. 4, illustrating a toothed plow element.

FIG. 7 is an enlarged vertical section taken on'line 77 of FIG. 1, showing the upper cutter bar in elevated position FIG. 8 is an enlarged detail vertical section taken on line 8-8 of FIG. 9.

FIG. 9 is an enlarged plan view of'the cutting and dislodging devices shown in FIG. 1, with the upper-bars broken away to show portions of the plow mechanism.

FIG. 10 shows one of the cutting and dislodging devices of FIG. 10, in an inner traveling position.

FIG. 11 is a horizontal section taken on line 1111 of FIG. 7.

FIG. 12 is a horizontal section taken on line 1212 of FIG. 3 showing part of the drive.

FIG. 13 is a longitudinal vertical section taken'on'line 13-13 of FIG. 12, showing further details of the drive.

FIGS; 14 and 15 are diagrammatic views'inplan showing the improved mining and loading machine in operaing position in amine, in accordance with the novel mining method.

FIG. 16 is a diagrammatic vertical section showing the manner in which the kerfs are formed to provide a mineral-core, and the associated coreripping and tearing member and dislodging wedge.

Theimproved mining and loading machine, as shown in the drawings, generally comprises a mobile base ll herein desirably acrawler base carrying a support or frame 2 on which a forwardly located cutting and. dislodging mechanism generally designated 3 is mounted.

The cutting and dislodging mechanism comprises a pair of cooperating horizontal cutting and dislodging devices or heads 4 extending forwardly and relatively angularly outwardly, with respect to the base. The dislodged and disintegrated mineral is moved rearwardly and inwardly toward a central conveyor 5 on the base frame and this conveyor extends rearwardly of the machine and terminates in a conventional laterally swingable and tiltable rear discharge portion 6. Carried at the forward portion of the base frame at the opposite sides of the conveyor are motors 7, desirably conventional electric motors, for driving the cutting and dislodging devices and the conveyor, and a motor 8 on the base frame serves to drive a hydraulic pump 9 and the endless treads 10 of the crawler base are driven by conventional hydraulic motors for moving the machine over the mine floor at a relatively slow mining speed or a relatively high travel ing speed, all in a conventional manner. The pump 9 supplies liquid under pressure to the various hydraulically operated devices of the machine, in a Well-known manner.

The cutting and dislodging devices or so-called heads 4, while oppositely disposed on the machine base, are substantially identical in design and each comprises a rearward frame 14 pivoted at 15 on a vertical pivot shaft 16 secured within spaced upper and lower portions of swingable supports in the form of lever arms 17 which are in turn pivotally mounted at 18 at their rearward portions on spaced lugs 19 integral with the base frame. Extensible power devices 20 and 2t), desirable conventional hydraulic jacks, pivotally connected to the swing ing frames 14 and 17 and the base frame serve to swing the cutting and dislodging devices or heads horizontally about their pivots 15 toward and from one another and for swinging the lever arms 17 horizontally about their pivots 18, and by trapping liquid within the jack cylinders the devices or heads and the lever arms 17 may be held rigidly in adjusted positions. The pivoted frames 14 of the cutting and dislodging devices or heads support elongated horizontal frames 21 which each carry a horizontal bottom plane cutter bar 22 having a guideway 23 about its margin and an endless cutter bit carrying cutter chain 24 guided in said guideway. Mounted on the frame 21 is an upper horizontal plane cutter bar 25 superimposed with respect to the lower bar and like wise having a guideway 26 about its margin for an endless cutter bit carrying cutter chain 27. The frames 14 support shrouding or housing members 28 (FIGS. 11 and 13) surrounding the rearward portions of the cutter chains for confining the disintegrated mineral in the paths of the cutter chains, thereby reducing falling of the loose mineral to the floor to facilitate floor clean-up. Evidently the kerf or channel cutting means may assume various other well-known forms.

Vertical adjusting devices, as for example, upright screws 29 are secured at 30 to and depend from the upper cutter bar 25 and these screws engage rotary nuts 31 journaled at 32 on the upper plate 33 of the frame 21. These nuts, when rotated, serve to move the screws axially to adjust the upper cutter bar vertically through a series of parallel horizontal planes to vary the elevation of the upper cutter bar. Suitable guiding means such as vertical telescopic guides 34 parallel with the screws serve to guide the upper cutter bar during its vertical adjustment.

Arranged intermediate the upper and lower cutter bars of each cutting and dislodging device is a horizontal guide frame 36 (FIGS. 4, 7 and 8) providing a horizontal guideway 37 along which an endless roller chain 38 is guided for orbital circulation and the guideway is sup ported near the upper portion of the lower frame 21, as shown most clearly in FIGS. 3 and 7, and each chain 38 carries at points spaced equally along its length plowlike ripping or tearing instruments or toothed plows (or planer elements) 39 and 40. Each plow has a frame 41 pivoted at 42 on lugs integral with certain of the chain links and spaced from the plow member pivots are rollers 43 engaging the outer periphery of the guide frame. Each plow member has a series of vertically spaced penetrating teeth or points 44. Evidently, usual reciprocatory planers may be employed in lieu of the plow elements 39 and 40.

The drives for the cutting and dislodging devices are similar and are operatively connected to the motors '7 and to the three superimposed endless chains 23, 26 and 38. In FIG. 12 a spur pinion 45 is secured to the motor power shaft 46 and meshes with a spur gear 47 secured to a parallel shaft 48, the latter being suitably journaled within a gear housing 49 on the base frame. Secured to the shaft 48 is a spur gear 59 meshing with and driving a spur gear 51 secured to a parallel shaft 52 likewise suitably journaled within the gear housing. The shaft 52 is connected through a conventional universal coupling 53 to a telescopic splined shaft 54 in turn connected by a universal coupling 55 to a horizontal shaft 56 suitably journaled within a gear housing 57 mounted on the pivoted frame 14. The shaft 56 is inclined forwardly and outwardly and has a beveled gear 58 secured to its forward end and meshing with a beveled gear 59 secured to a horizontal shaft 60 likewise suitably journaled within the gear housing 57.

The cutter bars and cutter chain orbits are generally trepezoidal in shape in plan and are widened at their rearward portions and project beyond the extreme rearward portions of the orbits of the plows to provide spaces between the projecting portions of the cutter bars for the gear housings and the pivotal mountings for the cutter bars on the forward portion of the base, as shown most clearly in FIGS. 9, 11 and 12.

Secured to the shaft 6%) is a spur gear 61 meshing with and driving a spur gear 62 suitably journaled on a horizontal longitudinally extending shaft 63 in turn journaled within the gear housing 57. The gear 63 is connected to the shaft by a friction clutch 64, and secured to the front end of the shaft 63 is a beveled gear 65 meshing with and driving a beveled gear 66 secured to the vertical shaft 67 (FIG. 13) journaled in upper and lower bearings 68 suitably supported within the frame 14. The shaft 66 has its axis aligned with the bar pivot axis. Keyed to the lower end of the shaft 67 is a chain sprocket 69 which engages and drives the cutter chain 24 of the bottom cutter bar. A coaxial shaft 70 has splined telescopic engagement with the shaft 67 and keyed to the upper end of the shaft 70 is a chain sprocket 71 arranged within the upper cutter bar and engaging and driving the upper cutter chain 27.

The gear 62 meshes with and drives a spur gear 72 (FIG. 12) secured to a shaft 73 arranged parallel with the shaft 63 and likewise suitably journaled within the gear housing 57. Secured to the shaft 73 is a spur gear 74 meshing with and driving a spur gear 75 secured to a parallel shaft 76 likewise suitably journaled within the gear housing. Secured to the shaft 76 is a beveled pinion 77 meshing with and driving a large bevel gear 78, in turn secured to a vertical shaft '79 journaled within the frame 14. Secured to the shaft 79 is a spur gear 80 which drives through a train of spur gears 81, 82 and 83 a vertical shaft 84 (see also FIG. 7) suitably journaled within the frame 14. This shaft drives at its upper end through a conventional planetary gear reduction unit 85 a coaxial tubular shaft 86 suitably journaled within the frame 21. Secured to and driven by the shaft 86 is a chain sprocket 87 which engages and drives the plowchain 38. The plow-chain of each cutting and dislodging device through the reduction gearing, above described, moves orbitally at a speed much slower than the speed of circulation of the cutter chains thereby to drive the plows at a relatively slow ripping or tearing speed.

Arranged within each of the cutter frames 21 is a motor 90, desirably a conventional hydraulic motor, supported by a bracket 91. Secured to the motor power shaft is a spur pinio'n 92 meshing with an intermediate gear 93 which in turn meshes with and drives a spur gear 94 secured to a vertical tubular shaft 5 by which a nut 31 is carried. Secured to the lower end of this shaft is a chain sprocket 96 which engages and drives an endless chain 97 which in turn engages and drives sprockets 98 and 99 secured to other vertical shafts 95 by which the other nuts 31 are carried. Thus by suitably operating the hydraulic motors 90 the nuts 31 may be concurrently driven to effect axial adjustment of the elevating screws 29 to vary the elevation of the upper cutter bars. Evidently, in lieu of the screw and nut adjusting devices other extensible power devices, such'as hydraulic jacks, may be employed.

The cutter chains and plows as they are circulated in their orbits engage, dislodge and disintegrate the mineral of a mine vein across the full working face, and move the disintegrated mineral rearwardly and inwardly toward the front receivingportion of the centrally located conveyor 5, and the conveyor receiving portion has a front nose 101 (FIG. 3) provided with a forward transverse penetrating edge 102 disposed adjacent to the floor surface. The cutting and dislodging devices may be fed rectilinearly forwardly by the crawler treads of the base thereby to dislodge the mineral across the full face, the nose of the conveyor penetrates the dislodged mineral at the floor level as the machine is advanced to aid in move: ment of the loose mineral onto theconveyor.

The inwardly and rearwardly moving runs of the cutter and plow chains during the cutting and dislodging operation aid the crawler base in the feeding of the machine toward the work thus in effect providing to some extent self feeding ability. Horizontal adjustment of the cutting and dislodging devices determines room width and provides flexibility for turning breakthroughs and maneuvering of the machine in the mine.

The general mode of operation of the improved mining and loading machine is as follows: The machine may be propelled from place to place about the mine by the endless crawler treads of the crawler base and steering of the machine may be effected by controlling the drive of the treads in a well-kown manner. As is usual in mining and loading machines of thecharacter disclosed, the base frame may have vertical tilting movement relative to the tread frames to hold thecutting and dislodging devices above the floor level during traveling and usually power jacks are employed to effect such tilt ing movement, as is well-known in the art. Whenthe working face is reached the cutting and dislodgingdevices may be lowered to the. floor level to the position shown in FIG. 2 and the hydraulic jacks may beop: erated to swing the devices laterally away from .each other to vary the room width as desired and liquid trapped within the jacks may serve to hold firmly.the devices in their laterally adjusted positions. The cutting and dislodging devices may then be fed rectilinearly forwardly toward the face by the'crawler treads. to sump the devices into the mineral of the mine ,vein. Evidently .by suitably operating the hydraulic motors 90 the ad: justing screws 29' may be operated to raise andlower the upper cutter bars to vary theoperating height of the cutting and dislod-gingdevices to suit different heights of coal seams and to aid in following vein-irregularities. As the machine is advanced, as shown in FIG. 14, along a straight path. toward the work by the crawler base the mineral is cut by the superimposed cutter chains and dislodged by the relatively slowly moving plows or planets and the dislodged mineral is moved inwardly and rearwardly toward the forward receiving portion of the centrally located conveyor 5 which in turn moves the disintegrated mineral rearwardly of the machine to a suitable point of delivery.

The cutting and dislodging devices, due to their novel arrangement, develop the ribs R of the room or mine passageway a material distance in advance of the center or apex portion P of the place leaving substantial central roof support well toward the vulnerable portions of the machine and the operators position. This central roof support, due to the angularly related positions of the cutting and dislodging devices, is substantially V- shaped in horizontal section as shown at S in FIG. 14, and the roof support thus provided is substantially continuous as the machine moves forwardly during its operation.

The superimposed cutter chains, as the cutting and dislodging devices are advanced rectilinearly toward the work, cut parallel superimposed channels or kerfs K (FIG. 16) in the mine vein thereby forming cores or projections C between the kerfs and the relatively slowly moving plows or plancrs between the upper and lower chains tear or rip away the cores or projections and move the dislodged mineral inwardly and rearwardly. When the upper cutter bars are elevated as shown in F165. 2, 7 and 16, the wedge breakers 103 on the upper cutter bars may engage and dislodge the upper portions of the mineral cores.

When it is desired to withdraw the cutting and dislodging devices from the working face of the mine vein and the machine may be retracted by the crawler base from the face and the devices maybe swung inwardly toward one another, as shown in FIG. 15, and the devices may be maintained in such inward positions during maneuvering of the machine and traveling of the machine about the mine. As the cutting and dislodging devices are swung inwardly the armlike supports or lever arms 17 swing outwardly from the sides of the central conveyor (FIGS. 10 and 15) to locate the pivots 15 of the devices in lateral positions to enable the devices to be brought relatively close together as shown.

When the cutter bars are swung inwardly toward one another as shown in FIG. 15 the outer lateral limits of the bars lie substantially within the projections of the sides of the base or machine width and height thereby not only to facilitate maneuvering of the machine but also to provide adequate space between the sides of the machine and the ribs and above the machine for the setting of roof props.

As a result of this invention an improved combined mining and loading machine is provided having improved cutting and dislodging devices whereby the mineral of a solid mine veinmay be dislodged and disintegrated in an improved manner. By the provision of the super-' imposed cutting devices for cutting parallel kerfs in the mineral of a mine vein to form a core of mineral between the kerfs and the intermediate relatively slowly moving plowlike or planer devices the mineral may be cut and dislodged in a more eflicient manner. The horizontal and vertical adjusting devices for the cutting and dislodgingdevices enable variable width places and veins of different heights to be cut and dislodged and enables the devices to follow vein-irregularities. Due to the novel arrangement of the cuttingand dislodging devices the mineral is not only mined out in an improved manner but by such an arrangement a novel mining method is attained whereby the roof is at all times supported close to the machine. The machine i relatively rugged and compact in design and flexible in operation, well adapted to meet the conditions encountered in low vein mining work. Other advantages of the invention willbe clearly apparent to those skilled in the art.

While there are in this application specifically described one embodiment which the invention, from its apparatus aspect, may assume in practice and one mode of practice of the invention, from its method aspect, it will be understood that thi invention may be modified and embodied in various other forms and operated in accordance with other methods without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a mining and loading machine, the combination comprising a support, a pair of laterally spaced elongated members having an end pivotally mounted on said support, jack means pivotally connected to said support and to said elongated members for swinging said elongated members toward and away from one another, pivotal mounting means for dislodging devices comprising swinging frames pivotally mounted at the other end of said elongated members and swingable horizontally about said first pivot to locate the pivots of Said devices in different lateral positions during swinging of said devices inwardly toward one another, and jack means pivotally connected to said support and to said dislodging devices for pivoting said dislodging devices relative to said elongated members and to said support in order to cause pivotal and bodily movement of said dislodging devices relative to said elongated members and said support, respectively, said first mentioned jack means being operable to swing said elongated member laterally away from one another for permitting said dislodging devices to be moved toward one another to avoid mutual interference of said dislodging devices.

2. A combination as set forth in claim 1 wherein said dislodging devices on said support include superimposed horizontal cutter bars having endless cutter chains guided for orbital circulation about their margins, plows movable orbitally intermediate said cutter bars, and means for moving said plows at a speed substantially slower than the speed of said cutter chains.

3. The combination, in a mining and loading machine comprising a support, a pair of cooperating horizontal cutting and dislodging devices extending angularly forwardly and outwardly with respect to said support, said devices being bodily adjustable horizontally to compensate for working faces of varying width, adjustable mounting means each of which have spaced parallel pivots with respective pivots of each of said mounting means connected to said support, means for swinging each of said devices about one of said pivots, and means for swinging each of said mounting means outwardlyabout said respective pivots a said devices swing inwardly about said one pivot in order to avoid mutual interference of said devices.

4. In a mining and loading machine, the combination comprising a support having spaced vertical pivots at the forward end thereof, elongated members having pivot receiving means at either end thereof being pivotally connected to said spaced vertical pivots, cutting and dislodging devices pivotally mounted on the other end of each of said members and extending forwardly and outwardly therefrom, means connected to said support for pivoting said members and said devices independently relative to said support so that said devices are movable within the projected lateral confines of said support without causing mutual interference thereof and motor operated driving means for said devices for concurrently driving the latter irrespective of the adjusted positions thereof comprising motors on said support and self-adjusting transmission connections between said motors and said devices respectively.

5. In combination, a support, a pair of superimposed horizontal cutter bars having endless cutter chains guided for orbital circulation about their margins, and orbitally movable plow devices arranged intermediate said upper and lower cutter bars, the orbit of said plow devices being substantially smaller than and lying within the orbits of said cutter chains, said cutter bars and cutter chain orbits being widened at their rearward portions rearwardly beyond the orbit of said plow devices to provide a space between the projecting portions of said cutter bars for the pivotal mounting for the cutter bars on the forward portion of said base.

6. A combination as set forth in claim 5 wherein said superimposed cutter bars are generally trapezoidal in shape in plan with the remote outer sides of said bars extending rearwardly and outwardly at a substantial angle with respect to the outer side of said orbit of said plow devices.

7. A combination as set forth in claim 5 wherein the rearward space between said cutter bars also receives a gear housing containing elements of the drive gearing for said cutter chains and said plow devices.

8. In a mining and loading machine, the combination comprising a support, a pair of elongated members having an end pivotally mounted on said support to swing toward and from one another, pivotal mounting means for dislodging devices comprising swinging frames pivotally mounted at the other end of said elongated members and swingable horizontally about said first pivot to locate the pivots of said devices in different lateral positions during swinging of said devices inwardly toward one another in order to avoid mutual interference of said devices, said dislodging devices include superimposed horizontal cutter bars having endless cutter chains guided for orbital circulation about their margins, plows movable orbitally intermediate said cutter bars, and means for moving said plows at a speed substantially slower than the speed of said cutter chains, said cutter chains being adapted to cut parallel kerfs in the mineral of a mine vein to form cores of mineral between such kerfs and said plows move in smaller orbits than said cutter chains and engage and remove the mineral-core as said cutting and dislodging mechanism is advanced toward the work and the upper cutter bar being adjustable in a vertical direction relative to the lower cutter bar and carries core breaker means beneath the same to break away the upper portion of the core when said upper cutter bar is in elevated position.

References Cited in the file of this patent UNITED STATES PATENTS 1,148,974 Kuhn et al Aug. 3, 1915 1,693,343 Morgan Nov. 27, 1928 1,726,963 McKinlay Sept. 3, 1929 2,261,160 Ioy Nov. 4, 1941 2,261,162 Joy Nov. 4, 1941 2,363,969 Jones Nov. 28, 1944 2,479,132 Peale Aug. 16, 1949 2,684,235 Joy July 20, 1954 2,699,930 Lobbe Jan. 18, 1955 2,709,878 Olson June 7, 1955 2,796,246 Joy June 8, 1957 2,780,448 Core et a1 Feb. 5, 1957 2,796,246 Joy June 19, 1957 2,879,980 Thornburgh et al Mar. 31, 1959 FOREIGN PATENTS 112,813 Germany Sept. 6, 1900 600,138 Great Britain Apr. 1, 1948 

